PB2064: RELAPSED/REFRACTORY HODGKIN LYMPHOMA PATIENTS TREATED WITH RADIOTHERAPY
Authors: F. Kallel, F. Kammoun, H. Ben Salah, L. Ghorbel, N. Toumi, M. Charfi, I. Ben Amor, I. Frikha, L. Khalifa, Y. Fakhfakh, O. Kassar, M. Medhafar, S. Hadiji, A. Khanfir, J. Daoued, M. Elloumi
Journal: HemaSphere (2022)

Background: Relapsed and refractory Hodgkin lymphoma (RR-HL) challenges clinicians to devise treatment strategies that are effective and safe. Besides salvage systemic therapy, the use of consolidative stem cell transplantation, new biologics, and immunotherapeutic approaches, radiation therapy remains an integral component of treatment for many patients and must be used effectively and judiciously. Aims: The purpose of this study is to describe the indications and the modalities of radiotherapy (RT) for patients with RR-HL in our center, as well as its therapeutic results. Methods: It is a retrospective study about adult patients with RR-HL, who were treated with salvage treatment including radiotherapy, at the university hospital of Sfax, Tunisia, between January 2008 and Mars 2020. Chemotherapy was given to patients in the hematology or oncology departments, and radiation therapy was given in the radiotherapy department, using linear accelerators or cobalt machines. Partial response (PR) was defined as a greater than 50% reduction in the product of the largest diameter and its perpendicular of measurable disease, lasting at least 1 month after radiotherapy. Results: Among the 55 patients having RR-HL during the study period, 19 underwent chemotherapy followed by RT. We did not note any case treated by radiotherapy alone. Eleven patients presented with refractory disease and 8 patients with relapse. No relapse in previously irradiated areas was noted. RT was palliative in 11 patients and consolidative for a residual mass in 8 patients. All patients with residual mass received a total of 36 Gy, except one patient who received 40 Gy. The radiation doses given were daily fractions of 2 Gy, 5 days per week. The majority of cases (5/8) had a residual mediastinal mass, but only one of them had a mediastinal bulky at the initial diagnosis of the disease. In one patient, RT was consolidative following autologous hematopoietic cell transplantation (ASCT). For palliative radiotherapy, it was received after a median of 2 lines of salvage chemotherapy (range 1- 4 lines), with a classic schedule of daily 2 Gy in almost all cases (9/11), and higher doses of 3 Gy/day in 2 cases. Involved-field radiotherapy was adopted in all 11 patients. Therapeutic response analysis showed that the majority of patients (88%) had at least a partial response. For patients with a chemoresistant disease and in indication of palliative RT, this alternative allowed for a partial response in half of the patients. Summary/Conclusion: Although concerns about the toxicities of RT will always be relevant to decision-making, our study showed that RT used as salvage therapy after standard-dose chemotherapy enhances local disease control in sites of relapsed or refractory HL in the majority of patients with residual disease, and in half of chemoresistant patients for whom palliative therapy was indicated.